Device for the adjustment of decorative stitch stencil in automatic zig-zag sewing machines



Aug. 25, 1959 K. BRANDT 2,900,837,

DEVICE FOR THE ADJUSTMENT 0F DECORATIVE STITCH STENCIL IN AUTOMATICZIG-ZAG SEWING MACHINES Flled Jan 14, 1957 5 Sheets-Sheet 1 IN V EN TOR.KURT BRANDT A #0 meys Aug. 25, 1959 K. BRANDT 2,900,337

DEVICE FOR THE ADJUSTMENT OF DECORATIVE STITCH STENCIL IN AUTOMATICZIG-ZA Filed Jan. 14, 1957 G SEWING MACHINES 5 Sheets-Sheet 2 Fig. 2

INVEN TOR.

K UR T BRA ND 7' Ahorneys Aug. 25, 1959 K. BRANDT 2,900,837

- DEVICE FOR THE ADJUSTMENT OF DECORATIVE STITCH STENCIL IN AUTOMATICZIG-ZAG SEWING MACHINES Filed Jan. 14, 1957 5 Sheets-Sheet 3 Fig.6

INVENTOR. KURT BRANDT A flameys Aug. 25, 1959 K. BRANDT 2,90

DEVICE FOR THE ADJUSTMENT OE DECORATIVE STITCH STENCIL IN AUTOMATICZIG-ZAG SEWING MACHINES Filed Jan. 14, 1957 5 Sheets-Sheet 4 INVENTOR. IKURT BRANDT BY P t A Nor/keys Aug. 25, 1959 K. BRANDT 2,900,837 7DEvTcEFoR THE ADJUSTMENT 0F DECORATIVE STITCH Y STENCIL IN AUTOMATICZIG-ZAG SEWING MACHINES Filed Jan. 14, 1957 5 Sheets-Sheet 5 IN V ENTOR.

KURT BRANDT BY r DEVICE FOR THE ADJUSTMENT OF DECORATIVE STITCH STENCIL1N AUTOMATIC ZIG-ZAG SEWING MACHINES Kurt Brandt, Augsburg, GermanyvApplication January 14, 1957, Serial No. 634,044 Claims priority,application Germany January 14, 1956 31 Claims. (Cl. 74--568) Thisinvention relates to a device for rapidly setting adjustable cams andmore particularly for setting the elements which control the formationof fancy stitches and fancy stitch combinations in automatic Zig-zagsewing machines.

When a zig-zag sewing machine equipped with noninterchangeable fashionstitch cams for producing automatic fancy stitches is required to formdecorative stitch patterns which call for the automatic control of thestroke of the feed dog as well as of other elements, at least two camsare required for the formation of one particular pattern. One cam isneeded to control the stroke of the feed dog and the other controls theposition or width of the stitch. Assuming for instance that ten camshave been-built into a machine, then the number of automatic basicpatterns would be restricted to five, if no allowance is made for thepossibility of forming combinations of different cams.

The present invention contemplates the formation of any desireddecorative pattern with the help of a single or a twin set of adjustablecams.

According to the invention one or several cam discs are each dividedinto several independent elements or segments which may be set by meansof a setting member resembling a key. Each one of a plurality ofdifferent key members produces a different decorative pattern; theformation of any desired decorative pattern therefore merely requiresthe availability of a comparatively small and cheap item, namely amemberresembling a key, whereas the costly set or sets of cams are requiredonce only.

Embodiments of the invention are illustrated by the accompanyingdrawings in which Fig. 1 is a longitudinal section of a cam drum withone fixed and eight adjustable cam discs, the discs being 5 representedas having been set for a particular pattern:

Fig. 2 is a section taken in the plane of a cam disc II (Fig. 1):

Fig. 3 is a section taken in the plane of a cam disc IIII (Fig. 1):

Fig. 4 is a view of the setting member which resembles a key:

Fig. 5 shows four different cross sections of the setting memberresembling a key: 1

Fig. 6 is a longitudinal section of a cam drum with four adjustable camdiscs and a setting member adapted to be unlocked by being turned:

Fig. 7 is a section taken in the plane of cam disc VI I-VII:

Fig. 8 "is a longitudinal section of a cam drum with four adjustable camdiscs and a setting member adapted to be unlocked by being turned:

Fig. 9 is a detail of a cam drum with a multi-part setting member:

Fig. 10 is a cross section of the setting member shown 70 i through 30.The cam body 44 of cam disc III-,-III

i F 09?? l r S le 4 United States Patent IC Patented Aug. 25, 1959 Fig.11 is a longitudinal section of a cam drum with two adjustable camdiscs; and

Fig. 12 is a section taken in the plane of cam disc IXIX.

Inside the body 1 of the sewing machine is a transverse shaft 4 mountedin bearings 2 and 3. The transverse shaft 4 is driven by the arm shaftthrough a worm 6 and a wormwheel 7. Secured to the transverse shaft 4(Fig. 1) is one set of cams 8 for controlling the stroke of the feeddog, not shown in the drawing, one set of cams 9 for controlling thewidth or position of the stitch, and possibly one non-adjustable cam forcontrolling the zigzag stitch mechanism.

The cam assemblies 8 and 9 are adjustable and to this end consist ofseveral members. Assuming, for instance that cam assembly 9 is requiredto control a stitch patoff surfaces.

tern comprising 24 stitches per pattern, in other words, that the needlewhich is likewise not shown is required to swing twelve times to theleft and twelve times to the right, then the cam assembly 9 must havetwelve projections 11 and twelve depressions 12 which in the illustratedexample (Fig. 1) are distributed between the adjacent cam discs II,II-II, III-Ill, IV'-IV. The cam disc I-I consists of an annular body 13provided with six slot-shaped recesses 14. Cam elements 15 are insertedinto these slot-shaped recesses 14, the flanks 16 and 17 of the camelements being held between the sides 18 and 19 of the slot-shapedrecesses 14 in the annular body 13. p I

The transverse shaft 4 has a central bore 20 for the reception of thekey-like setting members 21 and 22. Furthermore holes 23 are drilledradially into the transverse shaft 4, tappets 24 being slidably locatedinside the radial holes and adapted radially to displace the camelements 15.

The key-like setting members 21 and 22 are likewise provided withelevations 25 and depressions 26 so that the variations in the distances27 of the points of the contour from a central base cylinder, forinstance in plane A-B (Figs. 4 and 5) the outside contour of cam discI-1, will conformably represent the desired positions of the surfaces 28and 29 of the cam elements comprised in the assembly.

The heads of the cam elements 15 are provided with sloping lead-in andrun-off surfaces 30 and 31. Between the cam body 13 and the cam elements15 are either springs 32 which bear, on the one hand, against a shoulder33 in each recess of the cam body 13 and, on the other hand, at34'against the cam element urging the latter inwards in the direction ofthe arrow towards the cam centre, or alternatively there are arrangedbetween the cam body 13 and the cam elements 15, leaf springs 35 whichbear, on the one hand, against shoulders 36 in each recess and, on theother hand, against the cam elements at 38 and likewise urge the latterin the direction of the arrow, i.e. inwards towards the cam centre. Themeans described therefore create a direct connection by contact betweenthe surface 39 of the cam element 15 and the external contour 25 and 26of the key-like setting member 21.

Displaced through an angle of 15 alongside cam disc II is the next camdisc II-II (Fig. 3), which is contrived substantially in the same way ascam disc I-l excepting that the outer contours 40 of its cam elements 41are sections of are without inclined lead-in and run- The associated cambody 42 is coupled with cam body 13 of cam disc I-I by means of couplingpins 43.

Cam disc III-III is again constructed exactly like cam disc II butangularly displaced in relation to the latter is coupled with cam body42 of cam disc IIII by means of coupling pins 45.

Finally, alongside cam disc IIIIII, is a further cam disc IV--IV whichis displaced through a further angle of 15. Cam disc IV-IVis otherwiseconstructed exactly like cam disc HII.

The cam body 46 of this latter cam disc IV--IV is coupled with the cambody 44 of cam disc 1I1III by means of a coupling pin 47 which is at thesame time connected with an adjusting disc 49 adapted to be tightened onthe transverse shaft 4 by means of a grub screw 48. The adjusting disc49 is arranged to compress the entire cam assembly 9 by pushing itagainst the zigzag cam 10 which together with the wormwheel 7 is securedto the transverse shaft 4 by means of a common key 50.

The zig-zag cam 10 is axially supported by a sleeve 51, the wormwheel 7,the second sleeve 52, and a second cam assembly 8 which is retained byan adjusting disc 53 likewise adapted to be tightened on the transverseshaft 4. Cam assembly 8 is constructed in exactly the same way as camassembly 9 and the relative configuration of its cam elements for thecontrol of the varying stroke of the feed dog is likewise determined bythe contour of a second key-like member 22.

It will be understood from what has been said that the adjusting disc53, the cam assembly 8, the sleeve 52, the wormwheel 7, the sleeve 51,the zigzag cam 10, the cam assembly 9 and the adjusting disc 49, whenpushed on to the transverse shaft 4, -'will combine to form a cam drumwhich is rigidly mounted on the transverse shaft 4, and which has aperipheral surface of adjustably variable contour, the entire assemblybeing mounted on the body 1 of the sewing machine in bearings 2 and 3and capable of being rotated by the arm shaft through the worm 6.

The cam assembly 9 which can be pre-set by means of the key-like settingmember 21 is explored by a rocker 54 and cam followers 55 to 59 areadapted to be brought into play as required. The movement thus impartedto the rocker 54 is transmitted to the needle bar, not shown in thedrawing. On the other hand, cam assembly 8 which can be pre-set by meansof the key-like setting member 22 is explored by a second rocker 60 andits associated cam followers 61 to 64, likewise capable of being broughtinto play as required, but the resultant movements impressed upon rocker60 are transmitted to the feed dog actuating mechanism, likewise notshown.

The key-like setting members 21 and 22 carry fin-like propections 65 and66 which engage slots 67 and 68 in the transverse shaft 4 so that thekey-like members are forced to participate in the rotation of thetransverse shaft 4. Moreover a click catch 69 and 70 on each of thekey-like setting members 21 and 22 retains the latter axially in theirrequired positions inside the transverse shaft 4.

The embodiment of a cam assembly as illustrated in Fig. 6 with fouradjustable cam discs is contrived in the same way as the cam assembliesthat have been already described. The key-like setting member 100 is soshaped that the distance 103' (shown in dotted lines) is the same alongthe length of the key-like member where the tappets 103 make contacttherewith so that the key-like member will slip easily into the bore 101of the transverse shaft 102 when it is inserted therein. A spring-loadedretaining ball 104 built into the transverse shaft 102 slides along aslot 105 in the key-like member 100 and guides it into the shaft. Afterhaving been pushed home the key-like member 100 can be turned through anangle .106 when the retaining ball 104 will axially lock it inside theshaft. As a result of the turn given to the keylike member the tappets103 will be displaced by the external contour 107 of the'key-like member100 into the positionsrequire'd to push the cam elements into theappropriate positions for producing the desired decorative pattern.

The form of construction shown in Fig. 8 of a cam drum with fouradjustable cam discs is again constructed exactly like the precedingembodiment. However, the drawing shows the key-like setting member 108out of proper engagement. Not until the setting member 108 has beenpushed home in the direction of the arrow will the tappets slide up thecontour 109 of the key-like member 108 and be displaced into thepositions in which the cam elements will be set to produce the desireddecorative stitch pattern. The key-like member is axially held by theengagement of the click stops with the notches 111 and 112.

In another form of construction (Fig. 9) the setting member is embodiedin a sleeve 113 with a hollow interior 114 which serves for thereception of the key proper 115. The key 115 has a shank 116, 117 whichexactly fits into the bore 114 of the sleeve 113. Holes 118 are drilledtransversely into the sleeve 113 and these contain tappets 119. Springs120 urge the tappets 119 inwards in the direction of the arrow. When thesetting member 113 is pushed into the bore 121 of the transverse shaft122 for setting the cams, the key 115 must oc-= cupy the off positionshown in Fig. 9, and the retaining spring 123 must be in engagement withthe notch 124 in the key 115. In this position the contour 125 of thekey 115 will displace the tappets 119 into such a position that theirends are flush with the outer surface 126 of the sleeve 113. When thesetting member has been pushed into the bore 121 in the transverse shaft122 far enough to permit the retaining spn'ng 127 to click into notch128 and the blade 129 on the sleeve 113 to be in engagement with thegroove 130 in the transverse shaft 122, the setting member 113 will bein such a position that the tappets 119 in the sleeve axially align withthe tappets 131 in the transverse shaft 122.

The cam discs which are not specially shown in the drawing will now beset by pushing the key 115 home,

in the direction of the arrow into the in position, marked in dottedoutlines, when the retaining spring 123 will engage notch 132. Thecontour 125 machined into the shank of the key will now displace thetappets 119 outwards into their effective positions and by acting on thetappets 131 move the cam elements which are not specially shown into thepositions required [for the production of the corresponding decorativestitch pat-' tern.

In another form of construction (Fig. 11) a set of cams comprises twoadjustable cam discs. Again the cam assembly is constructed as has beendescribed. The tappets 133 associated with cam disc XX are offset insuch a manner that their ends are closely adjacent the tappets 134associated with cam disc IX-IX. Consequently, that part of the settingmember 135 which carries the tappet displacing contour 136 may be ofparticularly simple design.

I claim:

1. In a sewing machine having a zig-Zag stitch mechanism, a combinationvariable-contour cam assembly for controlling the zig-zag stitchmechanism and setting means for rapidly setting the contour of the camassembly, said combination cam assembly and setting means thereforcomprising a cam assembly incorporating several cam discs each discbeing subdivided into several elements each of which is capable ofindependent limited movement; and setting means carried by said camassembly for setting each of said elements into any position within itsrange of limited movement, whereby said cam assembly may be given anyone of an infinite number of contours.

2. In a sewing machine, a combination variablebeing subdivided intoseveral segments each of which is capable of independent limitedmovement; two setting means carried by said cam assemblies,respectively, for setting each of the respective segments thereof; anddriving means common to both of said assemblies for driving the same.

3. A device according to cilaim 1 wherein said elements of the camassembly are of similar shape.

4. A device according to claim 2 wherein the segments of each camassembly are of similar shape.

5. In a sewing machine having a zig-zag stitch mechanism, a combinationvariable-contour cam assembly for controlling the zigzag stitchmechanism and setting means for rapidly setting the contour of the camassembly, said combination cam assembly and setting means thereforcomprising a cam assembly incorporating several cam discs each discsubdivided into several segments each of which is capable of independentlimited movement; and setting means associated with said cam assemblyfor setting each of said segments into any position within its range oflimited movement, said setting means comprising a setting member whichis common to said segments and which is in the form of a key adapted tobe inserted and withdrawn to effect displacement of said independentlymoving segments, whereby depending upon the shape of the key, said camassembly may be given any one of an infinite number of contours.

6. In a sewing machine, a combination multiple variable-contour camassembly and setting means for rapidly setting the contour thereof,comprising two cam assemblies each consisting of several cam discs eachdisc being subdivided into several segments each of which is capable ofindependent limited movement; a keydike setting member for each camassembly, and driving means common to both of said assemblies fordriving the same.

7. A device according to claim 5, in which the keylike setting member inits eifective region has a circumferential conformation of which surfaceportions of said member which are contacted by said segments are locatedat different distances from the centre axis of the key-like settingmember.

8. A device according to claim 6 in which each keylike member in itseffective region has a circumferential conformation of which surfaceportions of said member which are contacted by said segments are locatedat different distances from the centre axis of the key-like settingmember.

9. A device according to claim 5 in which snap retention means areprovided for retaining the key-like setting member in the requiredposition.

10. A device according to claim 6 in which snap retention means areprovided for each key-like setting member so as to retain the same inits required position.

11, A device according to claim 5 in which the keylike member, wheninserted, is turned through a certain angle and is then secured againstwithdrawal by retention means.

12. A device according to claim 6 in which each keylike member, wheninserted, is turned through a certain angle and is then secured againstwithdrawal by retention means.

13. In a sewing machine having a zig-zag stitch mechanism, a combinationvariable-contour cam assembly for controlling the zigzag stitchmechanism and setting means for rapidly setting the contour of the camassembly, said combination cam assembly and setting means thereforcomprising a shaft; a cam assembly incorporating several cam discscarried upon said shaft, each disc being subdivided into severalsegments each of which is capable of independent limited movemovement,said shaft being formed with radial guide Ways within which saidsegments, respectively, are arranged for sliding movement and with anaxial bore communicating with said guide ways so that an actuationportion of each of said segments may project into said axial bore;spring means associated with said segments for continuously urging thesame inwardly so that actuating portions of said segments are constantlyurged into said axial bore; and a setting member in the form of a keyand common to said segments, said setting member being adapted to beinserted into and withdrawn from said axial bore to engage saidactuating portions ofsaid segments so as to effect displacement thereofagainst the force of said spring means so as to set each segment intoany position within its range of limited movement, whereby withdiiferent keys any one of an infinite number of different cam contoursof said cam assembly may be obtained.

14. In a sewing machine, a combination variablecontour cam assembly andsetting means for rapidly setting the contours thereof, comprising ashaft; two cam,

assemblies each consisting of several cam discs carried upon said shaft,each disc being subdivided into several segments each of which iscapable of independent limited movement, said shaft being formed withradial guide ways within which said segments are arranged for slidingmovement and with an 'axial bore communicating with said guide ways sothat an actuating portion of each of said segments may project into saidaxial bore; spring means associated with said segments for continuouslyurging the same inwardly so thatsaid actuating portions thereof areconstantly urged into said axial bore; two setting keys associated withsaid assemblies, respectively, each key being adapted to be insertedinto and withdrawn from said axial bore to engage the actuating portionsof those segments which are part of the respective assembly with whicheach key is associated to effect displacement of such segments againstthe force of said spring means, whereby with different keys differentcam contours of each cam assembly may be obtained, and driving means fordriving said shaft.

15. A device according to claim 5 including tappets provided inappropriate holes drilled into a transverse shaft which accommodates thekey, said tappets being interposed between the several segments of thecams and said key so as to constitute thrust transmitting connectionmeans for transmitting pressure from the key to said segments.

16. A device according to claim 6 including tappets provided inappropriate holes drilled into a transverse shaft which accommodates thekey, said tappets being interposed between the several segments of thecams and the respective key-like setting member so as to constitutethrust transmitting connection means for transmitting pressure from therespective keys to said segments.

17. A device according to claim 5 including tappets provided inappropriate holes drilled into a transverse shaft which accommodates thekey, said tappets being adjacent the key, are spheroid, conical, orsimilarly taper ing, so as to establish point-contact between the keyand said segments.

18. A device according to claim 1 in which said setting means are in theform of a key which may be insorted and withdrawn, and the cross-sectionof the key, in the region of each cam disc or the segments thereof, hasa contour the points of which vary in distance from the centre axis ofthe key member.

19. A device according to claim 2 in which each setting means is in theform of a key which may be inserted and withdrawn and the cross-sectionof each key, in the region of each cam disc or the segments thereof, hasa contour the points of which vary in. distance from the centre axis ofthe key member.

20. A device as claimed in claim 1 in which said setting means compriseseveral optionally insertable key like members with differently shapedcross-sections or circumferential conformations are provided eachadapted to effect displacement of the independently movable elements.

21. A device according to claim 2 in which each setting means comprisesseveral optionally insertable keylike members with diflerently shapedcross-sections :or circumferential conformations are provided eachadapted to effect displacement of the independently movable segments.

22. A device according to claim 5 in which said setting means alsoinclude several optionally insertable keylike members with differentlyshaped cross-sections or circumferential conformations are provided eachadapted to effect displacement of the independently movable segments.

23. A device according to claim 6 in which said setting means alsoinclude several optionally insertable keylike members with differentlyshaped cross-sections or circumferential conformations are provided eachadapted to effect displacement of the independently movable segments.

24. In a sewing machine having a zig-zag stitch mechanism, a combinationvariable-contour cam assembly for controlling the zigzag stitchmechanism and setting means for rapidly setting the contour of the camassembly, said combination cam assembly and setting means thereforcomprising a cam assembly incorporating several cam discs each discbeing subdivided into several elements each of which is capable ofindependent limited movement, said elements being mounted for slidingmovement in radial direction; spring means for continuously urging saidelements inwardly and therefore against the action of centrifugal force;and setting means associated with said cam assembly for setting each ofsaid elements against the action of said spring means into any positionwithin its range of limited movement, whereby said cam assembly may begiven any one of an infinite number of contours.

25. In a sewing machine having a zig-zag stitch mechanism, a combinationvariable-contour cam assembly for controlling the Zig-zag stitchmechanism and setting means for rapidly setting the contour of the camassembly, said combination cam assembly and setting means thereforcomprising a cam assembly incorporating several cam discs each discbeing subdivided into several segments each of which is capable ofindependent limited movement; a common setting member in the form of akey which is adapted to be inserted and withdrawn to effect displacementof eadh of said segments into any position within its range of limitedmovement; and compression spring means arranged located in chamber-likerecesses cut into said elements and the surfaces of said cam discs andbearing against said segments as well as against said surfaces of saidcam discs for continuously bringingsaid elements into contact with saidsetting member, whereby depending upon the shape of the key, said camassembly may be given any one of an infinite number of contours.

26. A device according to claim 6 including com-' pression springsbearing against the movable segments and acting centripetally thereon,and against the surfaces of thecam discs, said springs being located inchamber like recesses cut into the segments and the surfaces of the camdiscs.

27. A device according to claim 6 including leaf springs bearing againstthe movable segments and acting :centripetally thereon, and against thesurfaces of the cam discs, said springs being located in chamber likerecesses cut into the segments and the surfaces of the cam discs.

28. ,A device according to claim 5 in which there is provided for thereception of an inserted key-like member a cylindrical sleeve whichpossesses means .for creating an indirect positive connection betweenthe segments and the circumferential surface of the inserted key-likemember, the sleeve being insertable into a corresponding bore in atransverse shaft carrying said cam assembly and being adapted to besecured by catch means against displacement.

.29. A device according to claim 6 in which thereis provided forthereception of an inserted key-like member a cylindrical sleeve whichpossesses means for creating an indirect positive connection between thesegments and the circumferential surface of the inserted key-likemember, the sleeve being insertable into a corresponding bore in atransverse shaft carrying said cam assembly and being adapted tobesecured by catch means against displacement.

.30. A device according to claim 13 in which there is provided for thereception of an inserted key-like mem-- bera cylindrical sleeve whichpossesses means for creating an indirect positive connection between thesegments and the circumferential surface of the inserted key-likemember, the sleeve being insertable into a corresponding borein saidshaft and being adapted to be secured by catch means againstdisplacement.

31. A device according to claim 1 having two adjustable cam discs withassociated tappets arranged closely adjacent each other, whereas theassociated elements of the cams are spaced further apart, and:aPPropriate transmission members interposed between the tappets and theassociated elements.

References Cited in the file of this patent UNITED STATES PATENTS484,005 Gleason Oct. 11, .1892

703,028 Wildman -2 June 24, 1902 1,896,635 Lombardi Feb. 7, 19331,904,068 Meacock Apr. 18, 1933 2,025,463 Lombardi Dec. 24, 19352,100,876 Schneider Nov. 30, 1937 2,207,463 Lawson et a1. July 9, 19402,803,121 Ferraguti Aug. 20, 1957 FOREIGN PATENTS 108,606 Sweden Sept.28, 1943

